BEIJING, May 31 (Xinhua) -- China and Russia on Wednesday signed a plan to jointly monitor water quality in rivers and a lake bordering the two countries.

    According to the plan, they will record the water quality of the Argun, Heilong, Wusuli and Suifen rivers and Xingkai Lake from 2007 to 2010.

    The move comes after last year's heavy pollution of northeast China's Songhua River that flows into the Heilong River, called the Amur River in Russia, bordering the two countries.

    The pollution caused by a chemical plant explosion in the upper waters of the Songhua threatened the water supply of millions of residents along the river in China.

    Since then, the two countries have been in discussions on how to effectively protect water quality, with the establishment of a committee consisting of officials from China's State Environmental Protection Administration (SEPA) and the Russian Ministry of Natural Resources.

    The plan was signed at the end of the first meeting of the committee, which opened on Tuesday. The committee meeting is held once a year, alternating between the two countries. Enditem